Hacksaw.



A. H. HOFFMANN. HAGKSAW.

APPLIGATION FILED SEPT. 16, 1909.

9*?3'3431 n Patented Oct. 18, 1910.

WITNESSES IN ENTOR ALBERT H. HOFFMANN, OF FITCHBURG, MASSACHUSETTS.

HAGKSAW.

Specification of Letters Patent.

Application filed September 16, 1909.

Patented Oct. 18, 191i). Serial No. 518,060.

To all whom it may concern:

Be it known that I, ALBERT I-I. Horr- MANN, a citizen of the United States of America, residing at Fitchburg, in the county of Worcester and State of Massachusetts, have invented certain new and useful Improvements in Hacksaws, of which the following is a specification.

My invention relates to saws and more particularly to frames for hack saws, which are adjustable to receive various lengths of saw blades.

Heretofore great difficulty has been eX- perienced to provide an adjustable frame which shall be sufficiently rigid to withstand the wear and tear to which a saw of this type is constantly put. Most of the frames of this character are made of two pieces, one being adjustable upon the other.

The main disadvantage to this type of saw frame, is that the parts are bound to wear and work loose.

My invention has for its object the overcoming of this disadvantage and the provision of an adjustable frame which shall be as rigid as the ordinary solid frame, and at the same time one in which saw blades of different lengths may be easily inserted.

Another object of my invention is to provide such a frame, in which there is nothing whatever to work loose.

A still further obj ect of my invention is to provide a handle which, although loosely mounted in the frame, will not drop back when the saw blade is removed from the frame.

With the foregoing and other objects in view, my invention consists in such details of construction and combination of parts which shall be hereinafter more fully described and specifically pointed out in the claims.

In describing my invention in detail, reference will be had to the accompanying drawings, in which- Figure 1 is a side elevation of my improved saw frame, Fig. 2 is a detail view of a fragment of the frame and the slidable arm showing the mechanism for holding the arm in position, Fig. 8 is a vertical sectional view on the line A-A of Fig. 1, and, Fig. 4: is a detail view partly in section showing the handle shank and the adjacent parts.

In carrying out my invention I provide a frame 1 having one of its ends 2 bent downwardly to form a support for the handle and its shank. An arm 3 is slidable upon the top of this frame and said arm is provided with a removable stud 4, which passes through the aperture near its upper end. The stud t has a screw-threaded shanr 5 which receives a nut 6 for holding said stud in position. It will be understood that any suitable means may be employed in place of the screw-threaded shank and the nut received thereon. The inner end of the stud is bifurcated and has pivoted therein a pawl 7, which pawlis adapted to engage serrations or teeth 10 in the underside of the frame 1. These teeth may be spaced any suitable distance apart, but inasmuch as blades are manufactured in different sizes, which vary by inches, these teeth are preferably made one inch apart.

8 designates a spring fastened to the movable arm 3 in any suitable manner as, for instance, by a screw 11. The free end of the spring bears against the pawl 7 and holds the same in operative position in the teeth 10, said free end being preferably constructed with a roll 9 which is adapted to slide on the surface of the pawl when said pawl swings 'upon its pivot.

The lower end of the movable arm is provided with a suitable aperture through which is passed an adjustable stud 12 havinga screw-threaded shank 14 adapted to receive a thumb-nut 15. The other end of said stud is formed into a saw holder 13 having a bifurcated end with suitable apertures 16 therein through which is passed a pin 17 which is adapted to secure the saw blade 18 in the usual manner.

Through a suitable aperture in the downwardly bent end 2 of the saw frame, is passed a spindle 19 which forms the other saw holder Q6, as well as provides a shank for the handle of the frame. A collar 20 is suitably mounted upon a spindle 19 and provides a shoulder against which a spring 21 abuts, the other end of said spring contacting the inner surface of the member 2, thus tending to bear the shank 19 and the handle mounted thereon inwardly and preventing the same from sliding outwardly when the saw blade is removed, This spring also tends to hold the handle in such position as to prevent it from rotating as will be hereinafter further pointed out. In order that the handle may be removed from the frame, I preferably provide the collar y 20 with screw-threads which engage other threads upon the spindle 19. Upon theopposite side of the downwardly bent end 2, is formed an integral collar 22, which has a series of notches 23 disposed at diametrically opposite points in its outer periphery, said notches being adapted to receive the ends of a pin 24 which is passed through the shank 19. The pin 24 fitting into the notches 23 and being held in position by the action of the spring 2l prevents the handle from rotating when such rotation is not desired. 'Then it is desired to saw at an angle however, the saw may be adjusted by loosening the thumb-nut 15, drawing the handle and the shank I9 outwardly, then turning the same until the saw is atthe proper angle, whereupon the pin 24 may be allowed to rest in adjacent notches in the Collar 22 and the thumb-nut tightened.

From the foregoing it will be seen that I have provided a simple but rigid frame which has many novel points of advantage over those heretofore in use and which may be easily and cheaply constructed and readily assembled. In use it is simple and effective and as there are no parts to wear itis as durable as a solid frame.

I do not wish to limit myself to the exact details of construction hereinbefore set forth, but I desire it to be understood that slight changes in construction may be made without deviating from the spirit and scope of my invention.

I claim: l

1. In a saw, a frame having a downwardly turned end, an arm slidable on said frame, said arm carrying a stud having means for holding one end of a saw blade, said down` wardly turned end carrying a shank, a collar screw-threaded on said shank, a spring on said shank between said downwardly turned end and said collar, means on said shank engaging the other side of said downwardly turned end to hold said shank in various angular positions, and means on said shank for holding the other end of the saw blade.

2. In a saw, a frame having a downwardly turned end, an arm slidable on said frame, a stud in said arm having means for holding one end of a saw blade, a shank in said downwardly turned end having means for holding the other end of the saw blade, a collar on the inner end of said shank, said collar being removable whereby said shank maybe drawn from said downwardly turned end, a spring interposed between said collar and said end, and means in the shank engaging the other side of said downwardly turned end whereby said shank is held in a desired position.

In testimony where0f,I aiiiX my signature in the presence of two witnesses.

ALBERT H. HOFFMANN.

Vitnesses OTTO K. RIEDEL, ALFRED GELENA. 

